PRINCIPLES OF VETERINARY SURGERY 43 



tissues — the polymorphonuclear leucocyte, the lymphocyte, 

 the eosinophile and the mast-cell (the phagocytes) (by the 

 older authorities including Cohnheim and Metchnikoff, emi- 

 gration is considered the principal phenomenon of all in- 

 flammations)'; (3) productive, a form of inflammation in 

 which the proliferation of new cells is the main characteris- 

 tic; (4) specific or infectious granulomata, special inflam- 

 matory growths due to specific micro-organisms, not only 

 bacteria, as the glanders bacillus, but other fungi also, the 

 ray-fungus, botryomyces, etc. In nearly all these infectious 

 granulomata, the lesions are focal, the course is sub-acute or 

 chronic, resulting in circumscribed collections of granulation- 

 tissue. Granulomatous tumors usually continue to enlarge 

 as long as the micro-organisms continue to vegetate, and 

 when they die, secondary retrogressive changes take place 

 in the granulomata. Another marked characteristic of these 

 tumors is that the change produced in the tissue is so speci- 

 fied that in most cases it is possible to make a diagnosis by a 

 microscopical examination of the tissues without isolating 

 the parasites. Under this form of inflammation may be in- 

 cluded tuberculosis, actinomycosis, botryomycosis, glanders, 

 and farcin du boeuf. 



ANATOMICAL PROCESSES OF INFLAM- 

 MATION. 



These consist of four distinct phenomena on the part of 

 the tissues, viz: the changes which take place in the vessels, 

 the emigration of the leucocytes, the inflammatory exudates 

 and the changes in the fixed cells. These phenomena are the 

 same in essence as occur in every reparative process. 



VASCULAR CHANGES.— Marked changes in the 

 blood-vessels take place at the beginning of an inflammation 

 in vascular tissue. This is largely due to the stimulating 

 action of the irritant upon the vaso-motor nerves. However, 



